1. Field of the Invention
The present invention relates to a camera using a recording medium in which an object image obtained through a photographing optical system is electronically developed, and more particularly, to a device for performing a white balance adjustment when the image recorded in the recording medium is read therefrom, or when the image is developed by the recording medium.
2. Description of the Related Art
Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 5-2280 and U.S. Pat. No. 5,424,156, there is known a photographic material which is directly electronically developed so that the developed visible image can be immediately obtained. In this specification, such a recording medium is referred to as an electro-developing recording material, and an electronic still camera using the electro-developing recording material is referred to as an electro-developing type camera.
As a type of the electro-developing type camera which can take a color image, a construction, in which a single color image is obtained by a single shutter release operation, can be designed. In this construction, a color filter having red, green, and blue filter elements is disposed in front of the electro-developing recording medium.
However, the illuminance of light radiated on the electro-developing recording medium through each of the filter elements is not necessarily the same due to the characteristics of the color filter, or the characteristics of the illumination light radiated onto the object to be photographed. Therefore, it is necessary, for example, when reading the image from the electro-developing recording medium, to perform a white balance adjustment. Accordingly, the electro-developing type camera should be provided with a white balance sensor which detects the amount of energy of light of each of the color components, and a white balance signal processing circuit which converts the output signal of the white balance sensor to color temperature information, and carries out the white balance adjustment based on the color temperature information. Thus, the electric circuit construction in the electro-developing type camera should have a complex structure owing to the provision of a various kinds of circuits.